So all five have the same focal range, all five will work on cropped or full-frame bodies, and all five are L models. The choice between them is whether you want or need the brighter f2.8 aperture and or Image Stabilisation. The really interesting choice is between the f4 IS or the f2.8 non-IS as both cost roughly the same amount.

Since many of you own one of these models and have spent a lot of time weighing up the options, I'd like to invite owners to tell us why they went for their chosen model, what they think of it, and whether they would buy it again or go for a different one. Since many of you have posted comments about it before, feel free to copy and past your previous messages here.

This is to help future buyers of this lens decide. It also means if the question arises in the future, we can point new members towards this sticky thread.

And remember, if you are buying this lens, doing so through one of our partner shops will help support Cameralabs and keep it running!

I went for the f/4 IS first and then sold it in favor of the f/2.8 IS. Why?

First, I threw the non-IS versions out of the equation because I think IS is far too important in a tele-zoom to not have it.

The f/4 IS version is an absolutely FLAWLESS lens - no worries whatsoever about anything. Top build quality, sharp straight from f/4 on, quick focus, lightweight. The PERFECT lens for travelling and daylight sports.

BUT if you shoot events, weddings and portraits (which is what I do mostly) you might just not be quite happy knowing that there's a version which gathers double the amount of light and gives you a more pleasing bookeh. So for that reason, I got the 2.8 IS version.

However, this is a TOOL! It's heavy, it's rather soft at f/2.8 (especially at 200mm), it's heavy, the IS is actually a stop inferior to the one in the f/4 version and oh, did I mention that it's HEAVY? If you want something to travel, to just carry around for a walk or something similar, don't buy this lens! save yourself 700$ and get the f/4 IS, it's sharper and half the weight! If, however, you see your camera more as a working tool, don't care about the weight and need the f/2.8 aperture, get it and never look back - it's not gonna disappoint (I think thousands of pro's who make their living with this lens are enough evidence for that).

Oh and don't let the high price tag put you off. If you really want and/or need the f/2.8 aperture, you'll probably get it sooner or later anyway... don't make the same mistake like me and lose some money reselling other versions

my impressions:lightweight, easy to handle
AF is very swift
IS a bit noisy when activated (swirling sound)
Sometimes i feel f4 is not enough (indoor event such as sports, dance).
Super duper sharp and detailed
great for outdoor sports, portraits, still images
for walk around i feel it is too long in crop body.
for full frame body it is perfect.

I sold this lens when I get a full frame camera and get Sigma 70-200mm f/2.8 HSM (no IS) It suits my photography style better. I don't really worry too much about IS because I like freezing moving objects

If able to rewind, I think I will get Sigma 50-150mm / Tokina 50-135mm f/2.8 instead for Canon 40D. I think the focal length is more usable as walk around lens and f/2.8 is great. They are not heavy and expensive like 70-200mm f/2.8 version too.

This used to be one of my most difficult to decide on topics, and i could never make up my mind, after wanting the f/4 IS then the f/2.8 IS, and swapping back and forth, i have now decided to get the Sigma 70-200 f/2.8 HSM and a monopod. I know that really stirs things up but anyway, to be honest the Canon versions are rather expensive for a student, and i decided i really really wanted that 2.8 aperture, so the Sigma is hopefully the answer for me.

This is also a decision that i gave a lot of thought, in the end i went all out with the 70-200mm 2.8 IS. I knew right off the bat that i wanted the 2.8 version for better bokeh and better performance in low light. I always buy canon brand lenses.

A question for those who have tried both: at the same aperture, how does the f/2.8 compare in sharpness to the equivalent f/4 model? Particularly, how does the f/2.8 at f/4 compare with the f/4 at f/4?

From the photozone tests, the f/4 IS seems to be sharper than the f/2.8 IS at f/4.

A question for those who have tried both: at the same aperture, how does the f/2.8 compare in sharpness to the equivalent f/4 model? Particularly, how does the f/2.8 at f/4 compare with the f/4 at f/4?

From the photozone tests, the f/4 IS seems to be sharper than the f/2.8 IS at f/4.

I'm not really qualified to decide which of the four is best as the only one I've played with is the one I bought. I wanted IS and I didn't need f/2.8 so once I had read the glowing PhotoZone review the decision was made.

The lens saw service on my 400D where I didn't find the combination unbalanced as the left hand supported most of the weight, then my 40D and now, of course, my 5D MkII. The only drawback with using it on the full-framer is that I've lost that 1.6x crop factor but that loss is partially recouped by the high pixel count of the sensor.

I'd like to second what others have said above, especially Nostrum (the 2.8 @ f/4 is very very slightly worse than the 4.0 @ f/4, and yet the 2.8 is otherwise double as useful).

I've had the unique privilege of owning the f/4 IS, f/2.8, and f/2.8 IS.

There's a nice feel to the f/4, being all compact and easy to squeeze into a bag. And it's dreadfully sharp. Almost frightningly so. It's basically a prime, it's got that "pop" that a prime has.

But the 2.8 can just gather that much more light. On a bright, sunny day, it won't matter - sure. But I hardly get to shoot on bright, sunny days. It's rained almost every day here since spring, i work full time and go to school at night, and i live in a city. I need the biggest apertures I can get, because it's always a little too dim for photography. The 2.8 was the clear winner.

The IS vs non IS issue was a more complicated one. At first, it seemed like it was a no brainer. Why wouldn't you want your image stabilized? Why not? Because it costs $600 to do that. I have sooooooooooo many other things to spend that money on ... and I have very steady hands. For me, I was very happy without it.

I have the 1.4x and 2.0x extenders, both mk II. They stack. It's fun. When they're both stacked, i wish I had the IS. However, with both stacked, the images produced are so washed out, they're embarrassing. With just one extender, which is how I'll shoot when i'm doing sports, i have not regretted the lack of IS.

This used to be one of my most difficult to decide on topics, and i could never make up my mind, after wanting the f/4 IS then the f/2.8 IS, and swapping back and forth, i have now decided to get the Sigma 70-200 f/2.8 HSM and a monopod. I know that really stirs things up but anyway, to be honest the Canon versions are rather expensive for a student, and i decided i really really wanted that 2.8 aperture, so the Sigma is hopefully the answer for me.

How does the monopod compare to the IS? Sounds like a cost effective replacement. I think Canon claims about 3 to 4 stops improvement with IS, does a monopod gain similar improvements?

Good question - but I regret to tell you you're unlikely to get more than a stop or two out of a monopod - well, that's me anyway! If you'd like to go into more detail about monopods, please start a new thread in the tripods section, as this one should be about the four Canon lenses alone.